U.S. Pat. No. 5,940,273 (the 273 patent) discloses a semiconductor clamping device. FIG. 1 herein is FIG. 1 from the 273 patent and is used to describe the clamping device taught in the 273 patent. Referring to FIG. 1, the clamping device in the 273 patent teaches a single, centrally located (over semiconductor device (12)) pressure distribution member (48) that is used to establish a desired magnitude of compression force between semiconductor device (12) and associated components, namely heat dissipating devices (80) and (82) and electrical contact members (102). Initially, prior to complete assembly of the components shown in FIG. 1, the desired magnitude of compression force is applied to pressure distribution member (48) by compressing the pressure distribution member relative to jaw (18). To complete assembly, nuts (72) and (74) at one end of tie rods (22) and (24), respectively, are tightened to a position at which pressure distribution member (48) indicates the desired clamping pressure force has been applied between the semiconductor device and associated components. This occurs when washer (66) of the pressure distribution member, which washer was initially nonrotatable due to the applied compression force, is free to rotate.
Although the clamping device disclosed in the 273 patent works satisfactorily, the electrically conducting planar surfaces (86) of semiconductor device (12) in FIG. 1, continue to increase in surfaces areas, as exemplified, for example, by design advancements for a disc-type (also referred to as “hockey puck”) semiconductor device, such as a silicon controlled rectifier (SCR). A clamping device with a single pressure distribution member can lead to isolated hot spots, for example, on the interfacing planar surfaces of semiconductor device (12) and associated semiconductor components due to unequal compression forces across the diameter of the planar surfaces. Therefore there is a need for an improved apparatus and method of clamping together semiconductor devices and associated components to achieve uniform compression forces across interfacing planar surfaces.